Fuel cells that generate electric power using a fuel gas and an oxidizing gas have lately attracted attention. As the fuel gas, hydrogen gas is employed. However, general infrastructures needed as the supply means of hydrogen gas have not been established. Therefore, existing gas infrastructures, such as a town gas infrastructure, are utilized whereby hydrogen gas is generated from a supplied town gas, using a hydrogen generating apparatus. The hydrogen generating apparatus includes a reformer which causes a reforming reaction between raw material and water to produce a hydrogen containing gas, a shift converter which removes carbon monoxide contained in the generated hydrogen containing gas by a water gas shift reaction, and a CO oxidizing device which removes residual carbon monoxide present in the hydrogen containing gas by oxidation. Each of these constituent parts employs a respective catalyst suitable for the acceleration of its associated reaction. For example, the reformer uses a catalyst of Ru, Ni, or the like. The shift converter uses a catalyst of Cu—Zn or the like. The CO oxidizing device uses a catalyst of Ru or the like.
Meanwhile, an odorant for the purpose of detection of a gas leak is added to the town gas or other like gas supplied by an existing gas infrastructure. Currently, as the odorant, sulfur compounds including mercaptans (for example, tertiary-butylmercaptan), thiophenes (for example, tetrahydrothiophene), and sulfides (for example, dimethyl sulfide) have usually been used alone or in combination with one another. These sulfur compounds are poisoning components that cause the catalysts used in the aforesaid constituent parts of the hydrogen generating apparatus to undergo deterioration. Therefore, the hydrogen generating apparatus is generally equipped with a desulfurizer adapted to remove sulfur compounds from the town gas prior to its being supplied to the reformer. Such a type of desulfurizer includes a desulfurizer that uses a hydrogenated desulfurization reaction and a desulfurizer that uses an adsorbent. For example, as the desulfurizer that uses an adsorbent, there is a known desulfurizer provided with a zeolite-based adsorption-removal agent capable of adsorptive removal of sulfur compounds at room temperature (see Patent Document 1). In addition, there is a known zeolite based adsorption-removal agent improved so as to maintain the performance of desulfurization over long periods (see Patent Document 2).
Meanwhile, if raw material gas (town gas) containing therein sulfur compounds is continuously supplied to the desulfurizer, the performance of adsorption of the adsorption-removal agent will drop. In this case, the replacement of the desulfurizer itself or the adsorption-removal agent disposed therein is required. Therefore, there is proposed a desulfurizer in which is disposed an adsorption-removal agent with an indicator function capable of facilitating the decision of when to replace the adsorption-removal agent (see Patent Document 3).
Furthermore, there is a known system that calculates, based on the amount of fuel used, the service life of an adsorption-removal agent for displaying the time for replacement or transmitting it to an external maintenance terminal (see Patent Document 4).
In addition, there is a known technique in which, subject to the replacement of the desulfurizer or the like, warning information is displayed when the remaining service life of an article of consumption falls within a predetermined range, and if no response is made within a predetermined period of time since the displaying of such warning information, the system is automatically shut down (see Patent Document 5).    Patent Document 1: Japanese Laid-Open Patent Application Publication No. Hei. 10-237473    Patent Document 2: Japanese Laid-Open Patent Application Publication No. 2004-228016    Patent Document 3: Japanese Laid-Open Patent Application Publication No. 2002-358992    Patent Document 4: Japanese Laid-Open Patent Application Publication No. 2004-362856    Patent Document 5: Japanese Laid-Open Patent Application Publication No. 2002-298892